The guzheng also known as the Chinese zither, is a Chinese plucked string instrument with a more than 2,500-year history. It has 16 (or more) strings and movable bridges. The modern guzheng usually has 21 strings, and is 64 inches (1,600 mm) long. It has a large, resonant cavity made from wutong wood. Other components are often made from other woods for structural or decorative reasons. Guzheng players often wear fingerpicks, made from materials such as ivory, tortoiseshell, resin or hard plastic, on one or both hands.
The guzheng is plucked with plectra attached to four fingers of one or both hands. Traditional playing styles use the right hand to pluck notes and the left hand to change the pitch and produce vibrato by pressing the strings. Modern styles or advanced players use both hands to strike notes.
Ancient picks were made of ivory and, later, of tortoiseshell. Musical ornamentation includes a tremolo, with the left thumb and index finger rapidly plucking the same note. Another common ornamentation is a wide vibrato, achieved by repeatedly pressing the string to the left of the bridge with the left hand. This technique is used extensively in Chinese music and Korean gayageum music.
The guzheng is usually tuned in a major pentatonic scale with five notes to an octave.
According to wikipedia